Furnace



S. B. RUSSELL mama Filed Hay 2'7. 1

Patented Sept. 11, 192 8.

UNITED STATES 1,683,730 PATENT. OFFICE.

SILAS BENT RUSSELL, OF ST. LOUIS, MISSOURI.

FURNACE.

Application filed May 27, 1927. Serial No. 194,694.

This invention relates to furnaces and with regard to certain'more specific features to thermostatically cont-rolled. smokeless furnaces. For burning bituminous coal. Among the several objects of the invention may be noted the provision of a furnace hav- .ing a plurality of grates and fire boxes adapt ed to operate alternately in series or in parallel; the provision of a furnace of the class described equipped with-improved draft control means, adapted to be manually set for series operation of the furnace when firing has been completed, and adapted to be automatically set for parallel operation of the furnace after a predetermined temperature has been reached after firing; and the provision of a device of the class described which is simple in construction, economical and readily operable. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structure hereinafter described, and the scope of the application of which will be indicated in the following claims. 1

In the following drawings, in i which is illustrated one of various possible embodiments of the invention, i

Fig. 1 is a horizontal section of the furnace taken on line 1-1 of Fig.2, certain parts being omittedfor clarity, the view being primarily diagrammatic; i

Fig. 2 is a vertical section taken on line 22 of Fig.1, certain portions being broken away; 7 I

Fig. 3 is a vertical section taken on line 33 of Fig. 2; a

' Fig. 4 is an isometric: layout of one half of the damper controlsystem used in the present invention the same being located outside the jacket to be described Fig. 5 is a fragmentary plan view showing a thermostatic controlling element; and

Fig. 6 is a fragmentary side elevation of a portion of said thermostatic controlling element. 1

Corresponding reference characters inclicate corresponding parts throughout the several views of-the drawings.

Smokeless furnaces, making use of two coal beds operatingin series as regardsdraft, have been heretoforesdevised, but dificulties have been encountered in preventing the second grate of the second coal bed from burning 0ut..

This condition has existed because the hot burning gasespassing from one grate passed 'means for resetting them after a period of time, so that they will cause parallel operation of said coal beds. Referring now more particularly toFigs. 1 and 2, there is illustrated at numeral 1 a hot air heating jacket having an inlet? and circulating fines 5. This heating jacket 1 surrounds the improved. furnace construction comprising two fire pots 7 and 9 carrying grates 11 and 13 respectively. Below the grates 11 and 13 areash pits 15 and '17 equipped with cleanout doors 19 and 21 respectively. The fire pots 7 and 9 are provided with firing doors and 22, respectively, above said grates; 1 i I The primary draft to the furnace is supplied through an inlet 23 having cross connections 25 and 27, which lead fresh air be-. neath the grates 11 and 13 respectively. Dampers 29 and 31 are carried'in the connections 25 and 27. i r i The fire pot 7 is connected from a point ill above its'grate 11 to a point below the grate 13 of the fire pot 9 by way of a cross-connecting flue 33 having therein a damper 35; and

the fire pot 9 is connected from a point above its grate13 to apoint below the gratell of the fire pot 7 by way of a cross-connecting flue 37 having therein a damper 39.. The fiues33 and 37 are similar. 1

Each of the lines 33 and 37 has a connection 41 and 13 respectively with a chimney connection or breeching 45, leading to a chimney or other suitable draft inducing device (not shown). The connect-ions' ll and 13 witlithe cross fines 33 and 37 respectively arefmade at points between the fire pots 7 and .9, and

the said dampers, 35 and. .39, respectively, whereby it is made possible to operate the fire pots 7 and 9 in parallel whenever desired and under the alternate series conditions to be described hereinafter. The connections 41 and 43 carrydampers 47 and 49 respectively.

It will be evident hereinafter, that by properly setting the dampers 29, 31, 35, 39, 1? and 19, that three phases or conditions of operation may be accomplished, namely:

(1) The dampers 29, 35 and -19 may be open and the dampers 31, 39 and 47 may be shut at the same time. This condition is illustrated in Figsl to 3, giving aseries operation of the fire pots.

(2) Also, the dampers 29, 35 and 19 may be shut and the dampers '31, 39 and 17 may be open at the same time. This conditionis the inverse of that illustrated in Figs. 1 and 3 and recited under alternative (1), above, giving inverse series operation. a

(3) On the other hand, the ash pit "damp- I eis 29,, 31 andthebreeching dampers 47 and lilmay all be open, while the cross-connect,- ing-fiue dampers 35 and 39 are closed. This condition provides parallel operation of the fire pots. q i i i Under condition (1), also set. out in the drawings, the grate 11 hasjust been fired with fresh or green coalwhich causes smoke, while the grate 13 has had its charge burned down to a hot, smokelesscoke. The result is that air is drawn in beneath the grate 11 from the inlet 23 and the volatiles, which are driven from the freshly tired coal (especially from soft coal),ane passed over beneath the grate 13 and through the hot bed of coke and thence out to the chimney. This means that the volatiles-are positively put into a burning or combustible condition, because they. are forced topass through the hot coke. Smoke is thus eliminated. 1

Under condition 2, set out above, the action is similar, except that it is the inverse, fresh coal having just previously been fired into the fire pot 9 and the charge of the the pot 7 having been previously burned down to hot smokeless coke.

It is desirable that at sometime after firing each respective bed, that condition .3 be bmun'ht about automatically, because the fresh coal gradually ignites and sends over to the other grate such hot gases that the other,

grate lstlll dangerof being burned out. Furthermore, when these conditions are reached smoking from the fresh coal has stopped, because this coal now provides its own hi gh temperature for complete combustion. Theneed it"orseries operationhasceased. Said automatic action is thermostatically controlled. Under condition (3) each furnace draws its own supply of cool air from the inlet :23 and discharges directly to the stack, the cross flues 33 and r37 having their dampers 39 and 35 closed.

The inter connection and operation of the dampers is illustrated more particularly in Figs. 4: to (5, in whichis illustrated one of a twinset of controls. Qnly one control is shown be'ause the other is a duplicate and its connection is evident.

Referring now to Figs. 4 to 6, there are il lustrated diagrammatically said dampers 31, 35, and 47. which are all connected in the same operating, system shown. Dampers 29, 39 and 49 are connected together in order in a similar manner (not shown).

Dampers 31 and 35 are connected to operate together by a chain and sprocket system 51 and are controllable by a chain 53 passing over a sprocket on the shaft of the. damper The chain 53 passes over suitable guide and idler wheels 57 and 59 (above the jacket) and also over a control sprocket 61 and a sprocket 63 connected to the shalt of damper 4?.

The control sprocket 61 is made fast to a ratchet member (54 carrying an arm 6:) for manual setting purposes and a dog 67 normally engaged by a control pawl or click (l9 pressed into a holding position by a control spring 71. The mechanism is set into the Fig. 4 position by manually bringing the arm from its dotted line position to its solid line position, whereupon the pawl'69 holds the mechanism in place againstthe gravitational action of a weight; 73 suspended from the chain 53. A secondary weight 75 is used at the other end of the chain 53 for the purpose of maintaining it taut.

The pawl 69 also forms an armature for an electromagnet 77, wired into a battery or other suitable electric circuit 7 9 having therein a switch 81, adapted to be closed by the action of a thermostat 83, that is, whenever said thermostat reaches a predetern'lined temperature. One thermostat for one of the control systems is placed in each of the cross fiues 33, 37 at the region X (shown in Figs. 1 and 2). The thermostats 83 are sliow-n diagrammatically at X in Figs. 1 and 2 for clarity. W

Each thermostat 83 (F igs. 5 and 6) com prises a metal couple 85 pivotally supported at 8? and carrying at said pivot 87 an arm 89 for pressing said switch 81. The couple arm 85 rests upon a pin 91 so that when it is distorted due to increasing temperature, it causes rotation of the pivot 87 and movement of the arm 89 to close the switch 81, whereby the electro-magnet or solenoid 7 7 is energized and the pawl 69 pulled from under the do" 67, whereupon the descending weight 7 throws the dampers 31, 35 and 47 into positions alternate to the positions shown in Figs. 1, land 4, hereinafter known as their down positions. The up position shown, correspondsto that manually given by an operator immediately after having fired the pot 7. The otherdampers 29, 39 and 45) are already in down position such that the re quired series operation can be carried onand such that when the Fig. 1 damper system moves to its alternate down position, under ill) Inn

thermostatic control, that parallel operation of the furnaces or fire pot-s will be had as described under condition 3 above.

Parallel operation will proceed indefinitely until the fires burn out, unless the operator re-fires. Upon refiring the operator will fire the alternate pot 9 and pull the alternate damper control system (similar to the one shown in Fig. 4t) into the Fig. l position, whereupon dampers 29, 35 and 4-9 will be in closed position and dampers 31, 39 and l7 will be in open position. This is because dampers 31 and' l7 have automatically opened after the last firing and the' damper 35 has at the same time automatically close, while the dampers 29 and 49 are manually closed at the same time that the damper 39 is manually opened, said dampers 29, 39 and 49 being in the same type of system corresponding to that shown in Figs. 4 to 6. Each damper system controls the two inlets for one furnace and the breeching outlet of the other, as for ex ample in Fig. 4:, the system controls the two inlet dampers 31 and of ash pit 17 and the breeching damper 47 of the not 7. The corresponding damper system (not shown) controls the two inlet dampers 29 and 39 of the pit and the breeching damper 49 of the pot 9.

The operation of the furnace is as follows, assuming a hot coke bed in pot- 9 and a similar bed in pot 7, said pots operating in parallel. Both damper control systems are in their released positions with weights 73 down. Hence the conditions under alternative above, are maintained.

Next, the operator fires fresh coal into the pot 7 and pulls the corresponding arm or control 65, adapted to bring about resetting of the dampers 31, and 47 into the positions shown in the drawings and recited under series condition (1) above. This means that the furnaces are operating in series with pot 7 as the first in series and the pot 9 as the second in the series, the unburned volatiles from the fresh coal in pot 7 passing over and through the hot-coke of pot 9. The volatiles are thus positively ignited.

After the fresh coal begins to burn without smoke the temperature of the gases increases and the corresponding thermostat 83 is moved to close thecorresponding circuit 79 for permitting the described automatic change of the positions of dampers 81, and 47 so that the conditions under alternative again hold, that is, the furnaces are operating in parallel with the cool air coming through each grate.

At the next firing the operator fires the alternate fire pot 9 and pulls up the other corresponding lever or control to move dampers 29, 39 and 4:9, whereupon the conditions are reversed and series operation is had with the fire pot 9 as the first in the series and the fire pot 7 as the second in the series; This alternatescriesoperation continues until the other thermostat 83 is movedto close its corre-- sponding circuit 79 for permitting the automatic return in positions of dampers 29, 39 and 49 so that parallel operat on'ls again brought'about, that is, dampers 29, 31, 47

and as) are open, while dampers and 39 It is to be understood that the furnaces otherwise are taken care of in the ordinary manner, such as cleaning the grates and removing ashes and the like. his to be understood that the circuit ,7 9 need not be energized by means of a battery but may be energized in any other suitable way.

It is understood that the thermostat need not be of the'part-icular type indicated butmay be of a type using air or steam or other medium andoperating a suitable closing switch at a limiting temperature.

Furthermore, the entire furnace'may be one applicable to other systems'such as steam or hot water. V

The forces causing damper operation need not be gravitational but may arise from springs, compressed air, hydraulic pressure or the like.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageousresults attained. I

As many changes could bemade in carrying out the above constructionswithout de parting from the scope of the invention, it is intended that all matter contained in the above description or'shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim;

1. A furnace comprising a plurality of fire pots and means for inducing a draft't-hrough said pot-s alternately inseries and in parallel,

automatic means for changing said draft from seriesoperation to parallelopcration comprising a pluralityof dampers normally subject to forces for changing their setting, control means for temporarily resisting said forces, means operable at a predetermined temperature for releasing said control means so'that it does not resist said forces,whereby said forces actuate said dampers to change the damper setting to provide parallel operation, and manual means for resetting the mined rise in temperature and adapted upon closing to release said control means so that said control means does not resist said forces, whereby said forces actuate said dampers to change the damper setting to provide par allel operation, and manual means for resetting the dampers to provide series operation and for simultaneously re-applying said forces and said resisting control means, provided the operation of said thermostat and electric circuit will permit.

In testimony whereof, I have signed my name to this specification this 25th day of May, 1927. y

SILAS BENT RUSSELl-i. 

